• 한국동물위생학회지
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• 제41권2호
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• pp.85-89
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• 2018

This study was conducted to demonstrate the prevalence of subclinical ketosis in dairy cattle based on days in milk and herd level. Four to five blood samples were collected in five different lactation periods and analyzed for ${\beta}$-hydroxybutyrate using a Portable Ketone Test Kit. Subclinical ketosis was observed in 12 herds at prevalence of 6.3~57.1% depending on herd level, with four herds showing more than 40% subclinical ketosis prevalence. The distribution of subclinical ketosis in the early lactation period, high yield lactation period, mid lactation period, late lactation period and dry period was 9.5%, 27.5%, 36.8%, 27.9% and 12.5%, respectively. Clinical ketosis was only observed during early lactation (9.5%) and mid lactation (2%) period.

• 한국식품영양학회지
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• 제9권2호
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• pp.189-200
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• 1996

The purpose of this study was to find the effect of honey on the sugar metabolism In Sprague-Dawley rats. All experimental rats were fed ad libitum, for seven weeks, 68% saccharide diet anti 10% or 20% honey from acacia, sumac and miscellaneous flower honey, respectively, and sucrose. The amount of glucose in whole blood was increased in all groups fed with honey except the group fed with 10% sumac honey solution. The amount of fructosamine in serum of rat taken diet with honey solution was increased in comparison with normal group, control group, sucrose group. The amount of fructosamine in serum of rat taken diet with honey solution was high in order of sumac honey > miscellaneous flower honey > acacia honey. The amount of lactate and pyruvate in whole blood of rat taken diet with sucrose group or honey group were decreased in comparison with the normal group and control group. The amount of $\beta$-hydroxybutyrate in serum of rat taken diet with sucrose or honey was increased in comparison with the normal group, control group.

• Journal of the Korean Data and Information Science Society
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• 제26권4호
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• pp.915-921
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• 2015

본 연구는 젖소 35,645두의 검정기록, 총 294,834를 이용하여 1회 착유량과 아세톤 및 ${\beta}$-히드록시부틸산 (BHBA) 함량의 (공)유전력을 추정하기 위하여 수행되었다. 아세톤과 BHBA의 평균 함량은 원유 1리터당 각각 $135.54{\pm}96.29{\mu}mol$과 $61.08{\pm}66.76{\mu}mol$였으며, 상위군과 하위군간 아세톤과 BHBA 함량의 차이는 각각 $6.12{\mu}mol/L$과 $4.35{\mu}mol/L$로서 모두 유의적인 차이(p<0.01)를 나타내었다. 1회 착유량의 유전력은 0.18~0.21, 아세톤 함량은 0.11~0.13과 BHBA 함량은 0.01~0.02의 범위에서 추정되었다. 아세톤과 BHBA의 표현형상관과 유전상관은 각각 0.44와 0.48로 추정되었으며, BHBA 함량이 $500{\mu}mol/L$ 이상부터는 아세톤과의 상관관계가 현저히 낮아지는 현상을 나타내었다. 하위군에서 1회 착유량에 대한 아세톤과 $Log_e$아세톤의 공유전력은 각각 0.02와 0.16으로 추정된 반면, BHBA와 $Log_eBHBA$의 공유전력은 각각 0.26과 0.32로 아세톤의 추정치보다 높게 나타났으며, 이러한 결과는 전체자료로 추정된 결과와도 일치하였다. 따라서 아세톤 함량보다는 1회 착유량과 공유전력이 높은 BHBA 함량이 1회 착유량에 대한 선발을 통하여 간접선발 반응을 유도하는데 더 효과적이며, 지시형질로서 바람직하였다.

• Journal of the Korean Data and Information Science Society
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• 제28권6호
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• pp.1349-1360
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• 2017

케토시스 질병의 지표 형질인 milk ${\beta}$-hydroxybutyratc acid (BHBA), milk acetone, 그리고 사료효율의 지표형질 에너지보정유량 및 젖소의 주요 경제 형질인 산유량에 대한 유전력과 이들 간의 유전적 관계를 통하여 젖소의 케토시스 저항성 증진 가능성을 확인하기 위하여 본 연구를 수행하였다. 국내 젖소 14,397두에서 수집된 산유능력 검정자료 75,072건의 기록과 혈통기록 44,954두의 기록을 다형질 임의회귀 검정일 선형 모형을 이용하여 분석하였다. 케토시스 지표형질들의 유전력은 범위 0.06 ~ 0.15, 평균 0.08 (${\pm}0.03$)로 추정되었으며, 케토시스 지표형질들 간에 표현형 상관은 범위 0.73 ~ 0.90, 평균 0.78 (${\pm}0.04$), 유전 상관은 0.93 ~ 0.98 평균은 0.97 (${\pm}0.01$), milk BHBA, milk acetone과 산유량의 표현형 상관은 범위 -0.18 ~ -0.05 평균 -0.08 (${\pm}0.027$), 범위 -0.05 ~ -0.23, 평균 -0.1 (${\pm}0.041$), 유전상관은 -0.55 ~ 0.05, 평균 -0.16 (${\pm}0.18$), -0.62 ~ -0.04, 평균 -0.24 (${\pm}0.17$)로 각각 추정이 되었다. mill BHBA, milk acetone과 ECM의 표현형 상관관계는 0.056 (${\pm}0.023$), -0.04 (${\pm}0.029$), 유전적 관계는 평균 0.023 (${\pm}0.08$), 0.09 (${\pm}0.067$)로 각각 추정되었다. 따라서 산유능력 검정자료 수집 시 부가적으로 수집되는 케톤체를 이용하면 케토시스 저항성 증진을 할 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1299-1307
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• 2010

This study was conducted to evaluate the effect of dietary antioxidant and energy density on performance and antioxidative status in transition cows. Forty cows were randomly allocated to 4 dietary treatments in a $2{\times}2$ factorial design. High or low energy density diets (1.43 or 1.28 Mcal $NE_L$/kg DM, respectively) were formulated with or without antioxidant (AOX, a dry granular blend of ethoxyquin and tertiary-butylhydroquinone; 0 or 5 g/cow per d). These diets were fed to cows for 21 days pre-partum. During the post-partum period, all cows were fed the same lactation diets, and AOX treatment followed as for the pre-partum period. Feeding a high energy diet depressed the DMI, milk yield, and 4% fat-corrected milk (FCM) of cows. However, AOX inclusion in the diet improved the milk and 4% FCM yields. There was an interaction of energy density by AOX on milk protein, milk fat and total solids contents. Feeding a high energy diet pre-partum increased plasma glucose and ${\beta}$-hydroxybutyrate, whereas dietary AOX decreased plasma ${\beta}$-hydroxybutyrate value during the transition period. There were also interactions between time and treatment for plasma glutathione peroxidase activity and malondialdehyde content during the study. Cows fed high energy diets pre-partum had higher plasma glutathione peroxidase activity 3 days prior to parturition, compared with those on low energy diets. Inclusion of AOX in diets decreased plasma glutathione peroxidase activity in cows 3 and 10 days pre-partum. Addition of AOX significantly decreased malondialdehyde values at calving. Energy density induced marginal changes in fatty acid composition in the erythrocyte membrane 3 days post-partum, while AOX only significantly increased cis-9, trans-11 conjugated linoleic acid composition. The increase in fluidity of the erythrocyte membrane was only observed in the high energy treatment. It is suggested that a diet containing high energy density pre-partum may negatively affect the anti-oxidative status, DMI and subsequent performance. Addition of AOX may improve the anti-oxidative status and reduce plasma ${\beta}$-hydroxybutyrate, eventually resulting in improved lactation performance; the response to AOX addition was more pronounced on the high energy diet.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1031-1037
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• 2001

By a sequential action of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase, two molecules of acetyl-CoA re converted into D-3-hydroxybutyryl-CoA, a substrate for PHB synthase to form poly-3-hydroxybutyryl-CoA, a substrate for PHB synthase to form poly-3-hydroxybutyrate (PHB) of rhodobacter sphaeroides. The ${\beta}$-ketothiolase gene, phbA, and acetoacetyl-CoA reductase gene, phbB, were cloned and analyzed for their expression. Enzyme activities of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase showed constitutive levels during aerobic and photoheterotrophic growth of R. sphaeroides. In addition, no difference of each enzyme activity was observed between cells grown aerobically and photoheterotrophically. The constitutive level of the enzyme activities are regulated according to the growth phases along with growth conditions. Thus, phbAB expression is not determinative in regulating the PB content. On the other hand, phbA-deleted cell AZI accumulated only $10\%$ PHB of the wild-type, and an elevated dosage of phbAB in trans in R. sphaeroides resulted in a higher content of PHB, indicating that phbAB codes for the enzymes responsible for providing the main supply of subsyrate for PHB synthase. PHB formation by an alternative pathway that does not does not depend on the phbA-and phbB-coding enzymes is also proposed.

• 한국미생물·생명공학회지
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• 제18권6호
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• pp.607-612
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• 1990

생분해성 고분자로서 중요한 poly-$\beta$-hydroxybutyrate(PHB)의 생합성에 있어서 포도당과 암모늄농도의 영향을 규명하기 위하여 Alcaligenes eutrophus를 회분식으로 배양하였다. PHB는 질소원이 고갈되면서 생성되었고 건조세포무게의 약 80까지 축적되었다. 초기 포도당농도가 높을수록 세포성장과 PHB 합성은 억제되었지만 최종 세포농도와 건조세포무게에 대한 PHB 축적비는 증가하였다. 초기 암모늄농도가 낮을수록 최종 세포와 PHB 농도가 낮았지만 건조세포무게에 대한 PHB 축적비는 증가하였다. 배양도중 산소공급을 중단했을 때 세포성장과 PHB 합성이 중단되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.356-362
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• 2006

This study aimed to assess the effects of neutral detergent fiber (NDF) from rice straw on blood metabolites and productivity of dairy cows in the tropics. Eight Holstein ${\times}$ indigenous (75-87.5% Holstein) were randomly allocated to dietary treatments according to a double $4{\times}4$ Latin square design. Contents of roughage NDF from rice straw were 12.8, 14.8, 16.8 and 18.8% dry matter (DM) and concentrate NDF content was 10.2% DM, so that levels of dietary NDF were 23, 25, 27 and 29% DM. Dietary treatments were isonitrogenous and isocaloric diets. The average maximum and minimum temperature humidity index during the experimental period were 85.6 and 76.9, respectively. Plasma glucose (p<0.05), dry matter intake and 4% fat corrected milk (p<0.01) decreased with increasing contents of roughage NDF from rice straw, while rectal temperature, serum urea, cortisol, low density lipoprotein-cholesterol (p<0.05), serum total protein and ${\beta}$-hydroxybutyrate (p<0.01) increased. Serum triglyceride, total cholesterol and high density lipoprotein-cholesterol were not affected (p>0.05). Decreased rectal temperature and concentrations of serum cortisol were associated with decreasing levels of ${\beta}$-hydroxybutyrate and serum urea, but with increased concentrations of plasma glucose, DMI and 4% fat corrected milk indicating that lactating cows fed lower fiber diets were in lower oxidative stress. Therefore higher intake and metabolic efficiency in dairy cows fed diets lower in roughage NDF from rice straw would be of an advantage in productive systems under tropical conditions.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1445-1452
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• 2002

The present experiment was carried out to study the utilization of substrates in the mammary gland of crossbred Holstein Friesian during feeding on different types of roughage. Sixteen pregnant crossbred Holstein heifers consisted of two breed types of eight animals each; Holstein Friesian${\times}$Red Sindhi (50:50=50%HF) and Holstein Friesian${\times}$Red Sindhi (87.5:12.5=87.5%HF). Animals were divided into four groups of the same breed type in each group which were fed with either rice straw treated with 5% urea or pangola hay (Digitaria decumbens) as the source of roughage throughout the experiments. Four consecutive experimental periods were carried out in late pregnancy (20-23 days before parturition), early lactation (30 days postpartum), mid-lactation (120 days postpartum) and late lactation (210 days postpartum). Measurement of mammary blood flow in combining with measurement of AV difference was performed for the mammary uptake of substrates. In the period of lactation, udder blood flow was nearly three times higher than that of late pregnant period (p<0.05) in both 50%HF and 87.5%HF feeding on either hay or urea treated rice straw. During mid- and late lactation of both groups of 87.5%HF animals, mammary blood flow and milk yield showed decrease when compared to those during the early lactating period while the trends for persistency were apparent in both groups of 50%HF animals throughout experimental periods. The mean arterial plasma concentrations of glucose, acetate, $\beta$-hydroxybutyrate and free glycerol in each group remained constant throughout experimental periods. During late pregnancy in all groups, the AV difference and extraction ratio of glucose, $\beta$-hydroxybutyrate and triacylglycerol across the mammary gland markedly lowered (p<0.05), which coincided with a lower net uptake by the mammary gland in comparison to the early lactating period. The mean arterial plasma concentration, AV difference and extraction ratio for acetate showed no significant differences between late pregnancy and the early lactating period. The AV difference of free glycerol showed apparent release from mammary tissue during late pregnancy in all groups. In mid- and late lactation, the mammary uptake for glucose, acetate and $\beta$-hydroxybutyrate in both groups of 87.5%HF animals showed apparent decrease as compared to that in the early lactating period, whereas no appearances were observed in 50%HF animals feeding either hay or urea treated rice straw. The mean arterial plasma concentrations for free fatty acid (FFA) and triacylglycerol (C16 to C18) were higher in late pregnancy than in early lactation in both types of crossbred animals. The values of AV difference and the net uptake by the mammary gland for FFA were variable during late pregnancy and lactating periods in all groups. There were no significant differences for AV difference, extraction ratio and net uptake of triacylglycerol during lactation advance in both groups of 50%HF and 87.5%HF animals feeding either hay or urea treated rice straw. These results suggest that the adaptations to either hay or urea treated rice straw by the mammary gland of crossbred HF animals allow for an adequate nutrient supply during pregnancy and lactation. There is no difference in the mode of mammary uptake of substrates in the same crossbred animals in response to feeding hay or urea treated rice straw. The differences in utilizing nutrients by the mammary gland for milk production between 87.5%HF and 50%HF animals would be dependent on changes in both intra-mammary factors and extra-mammary factors.

• 생명과학회지
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• 제18권12호
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• pp.1625-1630
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• 2008

본 연구는 생분해성 플라스틱인 poly-${\beta}$-hydroxybutyrate (PHB)의 생산단가를 낮추기 위한 노력으로 저가의 기질로부터 PHB 대량생산을 위한 기초자료를 얻는데 그 목적을 두었다. Hemicellulose hydrolysate는 지구상에 풍부하게 존재하는 저가의 waste by-product로서 xylose가 많이 포함되어 있다. 본 연구에서는 xylose로부터 PHB를 생산할 수 있는 균주를 토양에서 분리하여, 분류학적 위치를 밝히고, 균체 생육 최적 조건, PHB 생산을 위한 최적 발효 배양 조건, PHB의 구조 확인 등을 검토 하였으며, 그 결과는 다음과 같다. 토양으로부터 분리한 균주 J-65는 형태학적, 배양적, 생화학적 및 partial 16S rRNA sequence에 근거하여 Bacillus megaterium로 동정하였다. B. megaterium J-65의 균체 생육 최적 조건은 온도 $37^{\circ}C$, 초발 pH 8.0이었으며 2% xylose, 0.25% $(NH_4)_2SO_4$, 0.3% $Na_2HPO_4{\cdot}12H_2O$, 0.1% $KH_2PO_4$였다. PHB 축적에 영향을 미치는 요인을 검토하기 위해 균체생육 최적배지에서 $37^{\circ}C$, 24시간 1차 배양한 후, 균체를 회수하여 각종 영양분이 결핍된 배지에 2차 배양을 실시한 결과 B. megaterium J-65는 균형생육조건(balanced-growth condition)에서 PHB를 합성하는 균주로 나타났다. PHB보다 물성이 향상된 PHB/HV 공중 합체를 생산하기 위하여 보조기질로 propionic acid를 첨가하였을 때, 0.1% propionic acid 농도에서 HV mol%가 14%인 PHB/HV 공중합체가 합성되었다. 5 l 용량의 발효조에 B. megaterium J-65를 회분배양하였을 때 배양 21시간에 건조균체량 10 g/l, PHB 3.5 g/l를 얻을 수 있었고, 유가배양을 실시한 결과 배양 48시간에 건조균체량 26.52g/l, PHB 9.28 g/l를 얻을 수 있었다. 생산된 PHB를 alkaline solution 처리와 chloroform을 이용한 유기용매 추출법을 이용하여 추출.정제한 후 Gas Chromatography로 정제를 확인하고 300MHz 1H-NMR을 실시한 결과 3-hydroxybutyrate의 homopolymer임을 확인하였다.